JURY MEMBERS :

Président/te of the jury :

• Prof Eric BONCOMPAGNI

Rapporteurs :

• Dr Isabelle FUDAL
• Dr Fabienne VAILLEAU
• Dr Thomas KROJ                                                       

Examinaters :

• Prof Michel HERNOULD           

Abstract :

Gall nematodes are microscopic parasitic worms capable of infesting the roots of thousands of plant species. They cause root deformities, reduce yields, degrade crops, and have a major economic impact. At the host root, they induce the formation of galls containing hypertrophied, multinucleated, and hypermetabolic feeding cells called “giant cells,” which constitute the nematode’s sole source of nutrients. Giant cells result from the redifferentiation of root cells. Molecules secreted by nematodes, known as “parasitism effectors,” play a central role in this cellular reprogramming; these are primarily proteins synthesized in the nematode’s esophageal glands and injected into plant cells via its stylet. Recent advances in nematode genomics and transcriptomics have led to the identification of a broad repertoire of effectors.

My research aims to characterize the function of these effectors. In particular, I want to identify their targets in the plant and characterize the cellular functions of the host that they manipulate to enable parasitism. The results obtained in recent years have confirmed the importance of manipulating the host’s immune system in the gall nematode’s parasitic strategy. They have also demonstrated the key role played by nuclear effectors in the transcriptional reprogramming necessary for the development of the nematode’s feeding site. A major finding was the characterization of an effector that targets the spliceosome and the identification of the key role played by alternative splicing during this interaction.

I intend to continue my investigations into the role played by alternative splicing during this interaction and to characterize other effectors capable of modulating the activity of the spliceosome or other nuclear protein complexes that could contribute significantly to the transcriptional and translational reprogramming of the host plant to enable the formation of new feeding structures. This research will contribute to a better understanding of the molecular dialogue that takes place between the nematode and its host, as well as to advancing knowledge about the function of genes involved in plant development and/or immunity. The identification of new genes essential for disease development—known as susceptibility genes—will also enable the development of innovative control strategies against these pests.     

Keywords: 

Gall nematodes; Plant-pathogen interactions; Effector proteins; Susceptibility genes